/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile.editor;

import proguard.classfile.attribute.ExceptionsAttribute;

/**
 * This class can add exceptions to a given exceptions attribute. Exceptions to be added must have been added to the
 * constant pool and filled out beforehand.
 *
 * @author Eric Lafortune
 */
public class ExceptionsAttributeEditor {
    private ExceptionsAttribute targetExceptionsAttribute;

    /**
     * Creates a new ExceptionsAttributeEditor that will edit exceptions in the given exceptions attribute.
     */
    public ExceptionsAttributeEditor(ExceptionsAttribute targetExceptionsAttribute) {
        this.targetExceptionsAttribute = targetExceptionsAttribute;
    }

    /**
     * Adds a given exception to the exceptions attribute.
     */
    public void addException(int exceptionIndex) {
        int exceptionIndexTableLength = targetExceptionsAttribute.u2exceptionIndexTableLength;
        int[] exceptionIndexTable = targetExceptionsAttribute.u2exceptionIndexTable;

        // Make sure there is enough space for the new exception.
        if (exceptionIndexTable.length <= exceptionIndexTableLength) {
            targetExceptionsAttribute.u2exceptionIndexTable = new int[exceptionIndexTableLength + 1];
            System.arraycopy(exceptionIndexTable, 0, targetExceptionsAttribute.u2exceptionIndexTable, 0,
                exceptionIndexTableLength);
            exceptionIndexTable = targetExceptionsAttribute.u2exceptionIndexTable;
        }

        // Add the exception.
        exceptionIndexTable[targetExceptionsAttribute.u2exceptionIndexTableLength++] = exceptionIndex;
    }
}
